A graph G is equitably k-colorable if its vertices can be partitioned into k independent sets in such a way that the number of vertices in any two sets differ by at most one. The smallest integer k for which such a coloring exists is known as the equitable chromatic number of G and it is denoted by x=( G). In this paper the problem of determining the value of equitable chromatic number for multicoronas of cubic graphs G◦ ^lH is studied. The problem of ordinary coloring of multicoronas of cubic graphs is solvable in polynomial time. The complexity of equitable coloring problem is an open question for these graphs. We provide some polynomially solvable cases of cubical multicoronas and give simple linear time algorithms for equitable coloring of such graphs which use at most x=( G◦ ^lH) + 1 colors in the remaining cases.

This article proposes and examines a solution in which the base-station for the fifth generation radio access network is simplified by using a single millimeter-wave oscillator in the central-station and distributing its millimeter-wave signal to the base-stations. The system is designed in such a way that the low-phase-noise signal generated by an opto-electronic oscillator is transmitted from the central-station to multiple base-stations via a passive optical network infrastructure. A novel flexible approach with a single-loop opto-electronic oscillator at the transmitting end and a tunable dispersion-compensation module at the receiving end(s) is proposed to distribute a power-penalty-free millimeter-wave signal in the radio access network. Power-penalty-free signal transmission from 10 MHz up to 45 GHz with an optical length of 20 km is achieved by a combination of a tunable dispersion-compensation module and an optical delay line. In addition, measurements with a fixed modulation frequency of 39 GHz and discretely incrementing optical fiber lengths from 0.625 km to 20 km are shown. Finally, a preliminary idea for an automatically controlled feedback-loop tuning system is proposed as a further research entry point.

The paper presents an analysis of using a TCS3430 light colour sensor to verify the chromaticity of navigation lighting installed at airports. These measurements can help determine the correct operation of the tested lamp using of specialised measuring devices. The emitted light colour is critical for pilots during flight operations such as take-off, landing and taxiing, especially in low visibility conditions. Chromaticity standards (in CIE1931 colour space) are specified in the relevant regulations of the European Union Aviation Safety Agency (EASA) and the International Civil Aviation Organisation (ICAO), and require regular inspection of each light point (both in-pavement and elevated lamps). Tests were carried out for various types of aviation navigation lighting lamps. The stability of measurements and possibilities of visualization on the chromaticity chart were assessed. The article also presents software that allows for quick verification of the operation of a given lamp, intended for airport maintenance services.